Seasonal changes in condition indices in adult mature and non-maturing burbot, Lota lota (L.), in the north-eastern Bothnian Bay, northern Finland

1990 ◽  
Vol 36 (2) ◽  
pp. 251-259 ◽  
Author(s):  
E. Pulliainen ◽  
K. Korhonen
Keyword(s):  
Seasonal Changes ◽  
Lota Lota ◽  
The North ◽  
North Eastern ◽  
Condition Indices ◽  
Bothnian Bay

Seasonal changes in the north-eastern Atlantic mackerel diet (Scomber scombrus) in the north of Spain (ICES Division VIIIc)

2005 ◽  
Vol 85 (2) ◽  
pp. 415-418 ◽  
Author(s):  
Ignacio Olaso ◽  
José L. Gutiérrez ◽  
Begoña Villamor ◽  
Pablo Carrera ◽  
Luis Valdés ◽  
...  
Keyword(s):  
Seasonal Changes ◽  
Content Volume ◽  
Gelatinous Zooplankton ◽  
East Atlantic ◽  
Atlantic Mackerel ◽  
North East ◽  
The North ◽  
North Eastern ◽  
Stomach Weight ◽  
North Of Spain

Seasonal changes in the diet of the Atlantic mackerel from the north-east Atlantic in ICES Division VIIIc during the period 1988–1999. The diet of juvenile (21–29 cm) and adult mackerel (30–45 cm) in this area in spring (the spawning season) and autumn varied in composition and size of prey. In spring, the average prey weight was 0·009 g and the number of prey was 180 individuals per stomach, with the average stomach content volume being 1·62 g (0·60% BW [body weight]), and 1·50 g (0·51% BW) when considering the empty stomachs. In autumn, the average prey weight was 0·28 g, the average number of prey per stomach was 17, and the average stomach weight that contained food was three times higher than in spring, and 2·3 times when considering the empty stomachs. In spring, the diet of the juveniles consisted of euphausiids, crustacean larvae and other zooplankton, whereas euphausiids formed 90% of the diet in the adults. In addition, during this period mackerel were cannibalistic, feeding on their own eggs. In autumn, the juveniles ate hyperiids and other, mainly gelatinous zooplankton, whereas for the adults blue whiting were clearly important, since they comprised 90% of the stomach weight.

scholarly journals Seasonal changes in phytoplankton on the north-eastern shelf of Kangaroo Island (South Australia) in 2012 and 2013

Oceanologia ◽  
2015 ◽  
Vol 57 (3) ◽  
pp. 251-262 ◽  
Author(s):  
Sergio Balzano ◽  
Amanda V. Ellis ◽  
Charlotte Le Lan ◽  
Sophie C. Leterme
Keyword(s):  
Seasonal Changes ◽  
South Australia ◽  
The North ◽  
North Eastern ◽  
Eastern Shelf

scholarly journals Larval Anisakis simplex B (Nematoda: Ascaridoidea) of short-finned squid (Cephalopoda: Ommastrephidae) in north-west Spain

1999 ◽  
Vol 79 (1) ◽  
pp. 65-72 ◽  
Author(s):  
S. Pascual ◽  
A.F. Gonzalez ◽  
C. Arias ◽  
A. Guerra
Keyword(s):  
Seasonal Changes ◽  
Anisakis Simplex ◽  
Type I ◽  
Allometric Growth ◽  
North West ◽  
The North ◽  
North Eastern ◽  
Almost All ◽  
Anisakid Nematodes

The role of the ommastrephid squids Illex coindetii and Todaropsis eblanae (Mollusca: Cephalopoda) collected from two areas in the north-eastern Atlantic waters (north-west Spain) as hosts for larval ascaridoid nematodes was examined from November 1992 to November 1993. The morphology, morphometric growth, population dynamics and electrophoretic identification of the anisakid nematodes was described. The correspondence of Anisakis type I larvae recovered from both squid species within the sibling species Anisakis simplex B is confirmed by comparative data on morphology, morphometry, and genetic evidences. Almost all somatic structures showed progressive and continuous allometric growth corresponding with increase in worm length. Seasonal changes in parasite population levels were evident in both sampling areas.

scholarly journals Seasonal influences on surface ozone variability in continental South Africa and implications for air quality

2018 ◽  
Author(s):  
Tracey Leah Laban ◽  
Pieter Gideon van Zyl ◽  
Johan Paul Beukes ◽  
Ville Vakkari ◽  
Kerneels Jaars ◽  
...  
Keyword(s):  
South Africa ◽  
Air Quality ◽  
South African ◽  
Biomass Burning ◽  
Southern Africa ◽  
Seasonal Changes ◽  
The North ◽  
North Eastern ◽  
The Relationship ◽  
Surface O3

Abstract. Although elevated ozone (O3) concentrations are observed in many areas within continental southern Africa, few studies have investigated the regional atmospheric chemistry and dominant atmospheric processes driving surface O3 formation in this region. The aim of this study was to conduct an assessment of comprehensive continuous surface O3 measurements performed at four sites located in continental South Africa. These sites were representative of regional background (Welgegund and Botsalano) and industrial regions (Marikana and Elandsfontein) in the north-eastern interior in South Africa as indicated by comparison with other sites in this region. The regional O3 problem was also shown with O3 concentrations being higher than 40 ppb at many sites in the north-eastern interior, while the South African air quality standard limit for O3 was regularly exceeded at the four sites in this study. O3 levels were generally lower at other background sites in the Southern Hemisphere compared to the South African sites, while similar seasonal patterns were observed. The temporal O3 patterns observed at the four sites resembled typical trends for O3 in continental South Africa, i.e. O3 concentration peaking in late winter and early spring, and daytime O3 peaks associated with increased photochemical production. The seasonal O3 trends observed in continental South Africa were mainly attributed to the seasonal changes in emissions of O3 precursor species and changes in meteorological conditions. Increased O3 concentrations in winter were indicative of increased emissions of O3 precursors from household combustion for space heating and the concentration of low-level pollutants near the surface. A spring maximum was observed at all the sites, which was attributed to increased regional biomass burning during this time. Source area maps of O3 and CO indicated significantly higher O3 and CO concentrations associated with air masses passing over a region where a large number of seasonal open biomass burning occurred in southern Africa, which indicated CO associated with open biomass burning as a major source of O3 in continental South Africa. The relationship between O3, NOx and CO indicated a strong dependence of O3 on CO, while O3 levels remained relatively constant or decreased with increasing NOx. The seasonal changes in the relationship between O3 and precursors species also reflected the seasonal changes in sources of precursors. The instantaneous production rate of O3, P(O3), calculated at Welgegund indicated that at least 40 % of O3 production occurred in the VOC-limited regime. These relationships between O3 concentrations and P(O3) with O3 precursor species revealed that large parts of the regional background in continental South Africa can be considered CO- or VOC-limited, which can be attributed to high anthropogenic emissions of NOx in the interior of South Africa. It was indicated that the appropriate emission control strategy should be CO (and VOC) reduction associated with household combustion and regional open biomass burning to effectively reduce O3 pollution in continental South Africa.

Discussion on “The grinding wheel and production” at the North-Eastern Section of the Institution

1942 ◽  
Vol 21 (8) ◽  
pp. 315
Author(s):  
Bowen ◽  
Vickery ◽  
Buchanan ◽  
Swallow ◽  
Perks ◽  
...  
Keyword(s):  
Grinding Wheel ◽  
The North ◽  
North Eastern

The influence of submesoscale eddies on hydrochemical parameters and structural and functional characteristics of phytoplankton in the north-eastern part of the Black Sea

2019 ◽  
pp. 24-40
Author(s):  
Sergey B. Kuklev ◽  
Vladimir A. Silkin ◽  
Valeriy K. Chasovnikov ◽  
Andrey G. Zatsepin ◽  
Larisa A. Pautova ◽  
...  
Keyword(s):  
Anticyclonic Eddy ◽  
The Black Sea ◽  
Hydrochemical Parameters ◽  
North East ◽  
The North ◽  
Seasonal Thermocline ◽  
North Eastern ◽  
Quantitative Indicators ◽  
The City ◽  
North Eastern Part

On June 7, 2018, a sub-mesoscale anticyclonic eddy induced by the wind (north-east) was registered on the shelf in the area of the city of Gelendzhik. With the help of field multidisciplinary expedition ship surveys, it was shown that this eddy exists in the layer above the seasonal thermocline. At the periphery of the eddy weak variability of hydrochemical parameters and quantitative indicators of phytoplankton were recorded. The result of the formation of such eddy structure was a shift in the structure of phytoplankton – the annual observed coccolithophores bloom was not registered.

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